1. Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
2. Department of Medicine and Surgery, Clinic of Infectious Diseases, University of Perugia, Perugia, Italy
3. Medical Microbiology Section, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
4. Centre for Magnetic Resonance, University of Florence, Sesto Fiorentino, Italy
5. Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
6. Istituto Officina dei Materiali-IOM, National Research Council-CNR, Perugia, Italy
7. Department of Physics and Geology, University of Perugia, Perugia, Italy